This invention relates to a film suction plate for a process camera, on which various sizes of films may be held by using a suction means such as a vacuum pump connected to the film suction plate.
A conventional film suction plate is shown in FIGS. 1 and 2. A base plate 1 of an aluminum casting, or the like, is provided concentrically with a plurality of rectangular frame-shape ventilating grooves 2 in its front surface. The grooved front surface of the base plate 1 is covered by a perforated plate 4 having a plurality of small suction holes 3 which are aligned along the ventilating grooves 2. Each ventilating groove 2 is open to the rear surface of the base plate 1 via an opening 5. The openings 5 are connected to a suction means (not shown) such as a vacuum pump, or the like, via a suction area switch valve means 6 and a suction pipe 7. The suction area switch valve means 6 is adapted to open or close each opening 5.
However, this conventional film suction plate has disadvantages and inconveniences. For example, the production of the base plate 1 requires a lot of time and labor, and thus it costs high. The base plate 1 is large and heavy, and accordingly it is inconvenient to handle it. Further, the suction area of the surface of the base plate 1 is changed by the suction area switch valve means 6 depending on the size of each film to be held.